Springs or balance springs (spiral spring) of a mechanical oscillating system can be manufactured from silicon and its surfaces can be provided with a layer of silicon oxide for improving the mechanical stability and for temperature compensation. Especially when the silicon oxide layer has been applied thermally, in the case of layer thicknesses which would be required for optimal temperature compensation, i.e., in case of thicknesses greater than 4 μm, there is a danger of deformation, at least partial deformation of the balance spring, which then leads to adverse effects on the accuracy of the oscillating system and/or non-reproducible conditions in production.